A suction filter for a fuel supply apparatus is known in the art for filtering fuel, which is sucked into a suction port of a fuel pump provided in a fuel tank. It is required for the suction filter to increase a surface area of a filter element. In a case that the surface area for the filter element is not sufficiently assured, life duration of the filter element is remarkably decreased due to clogging. In addition, a pressure loss for fuel suction is increased due to the clogging, to thereby generate vapors. As a result, a pump performance is likely to decrease.
For example, as disclosed in Japanese Patent Publication No. 2002-028418, a filter element is formed in a cylindrical shape having a bottom portion so as to increase a surface area thereof. According to such a prior art, the bottom portion of the filter element faces to an inner bottom surface of a fuel tank, so that fuel in the fuel tank is sucked into a fuel pump through such bottom portion of the filter element. According to such a structure, a fuel suction performance (a fuel cut-off performance) can be improved.
According to the suction filter of the above prior art, however, the filter element is formed in the cylindrical shape with the bottom portion in such a manner that a core member (which is connected to a suction port of the fuel pump) is immersed into water solution of textile material. A longer time is necessary to manufacture such filter element. It is, therefore, a disadvantage that productivity may be decreased.